The invention relates to capacitors within a motor; capacitors have been used in the past as connected to an electric motor. Such motors may be single-phase induction motors, with a capacitor connected to a winding to establish a split phase, primarily to establish starting torque, and the typical motor of this type has a metal, cylindrical can housing, the capacitor mounted on the outside of the electric motor frame. In a few cases, the manufacturer has found room to place the capacitor inside the motor, within the end bell, for example, but this entails using an elongated end bell and elongated motor to provide space for such a capacitor.
I have previously disclosed a half-pitch capacitor induction motor operable on single-phase, and having balanced main and auxiliary windings, in U.S. Pat. No. 4,371,802. Such a motor has coils surrounding individual pole pieces rather than the usual distributed winding most often found in single-phase induction motors, yet in the motor covered by that U.S. patent the capacitor was mounted externally to the motor.
In the food processing industry, for example, sanitation is essential, and a number of electric motors are used, such as those driving fans for refrigeration equipment. In the food processing industry, it is often mandatory to hose down all equipment with a water stream once a week, or even once a day. The electric motors, therefore, must be capable of withstanding these water splash conditions, and with the prior art externally mounted capacitors, there was always the problem of properly sealing the interconnection between the metal capacitor housing and the motor housing, because electrical leads had to pass between the two. Because of this problem, capacitor-type motors were often avoided in the food processing industry, and ordinary resistance split-phase, single-phase induction motors were utilized instead, because they had a motor housing which could be more effectively sealed against the water splashing during the cleaning process.